Islamic Calendar

The Islamic Calendar, used by Muslims, is based on the moon. It has 12 months of either 29 or 30 days. Eleven times, every 30 years, an extra day is added to keep the calendar in time with the moon, not the seasons.

Since the Islamic year is just 354 or 355 days long, holidays move backward through the seasons, and each year, a holiday comes eleven days or sooner. In 33 years, the holiday is back where it started.

In the Qur'an, Islamic scripture commands the faithful to mark time by the cycles of the moon:

They ask thee
the New Moons
Say: They are but signs
To mark fixed periods of time
In (the affairs of) men
And for Pilgrimage. (II:189)
The number of months
In the sight of Allah
Is twelve (in a year)
So ordained by Him
The day He created
The heavens and the earth;
Of them four are sacred;
That is the straight usage
So wrong not yourselves
Therein, and fight the Pagans. (IX: 36)

The Islamic lunar calendar has historical and spiritual significance. First, it is a reflection of the lack of agriculture in this nomadic society. The calendar is not tied to the seasons of the solar year, which agrarian societies depend on and which were the probable origin of the first human calendar systems. Since Islamic culture had no need to mark the seasons – and some wags may suggest that Arabia, where Islam originated, has only one season anyway – they could abandon without consequence the solar calendar used by the unbelievers.

Second, their calendar serves much the same purpose as the Christian season of Lent – to remind the faithful of sacrifice and to prepare them for sacrifice in their own lives. Early Muslim holy men, when fashioning the modern Islamic calendar, chose to start it on July 16, 622 C.E., the year of the Hegira – Mohammed’s flight from Mecca – rather than Mohammed’s birth, ascension, or revelation. This notion stands in stark contrast to the Christian calendar, which nominally begins in the birth year of Jesus Christ, and symbolizes rebirth and redemption for all believers.

Not only does the start of the calendar call Muslims to contemplate sacrifice, but so do the months therein. Of the Islamic months, four are sacred. To Westerners, the best-known of these is the month of Ramadan, during which believers fast from dawn to dusk and focus on worship and contemplation.

Third, the Islamic calendar enables believers to comply with the will of Allah as written in the Qur’an. The scripture sets out strict instructions on how Muslims are to live their lives during the sacred months. The only way for Muslims to know when these instructions apply is to carefully track the lunar months. If they fail to do this, they are like the unbelievers:

Verily the transposing
(Of a prohibited month)
Is an addition to Unbelief:
The Unbelievers are led
To wrong thereby: for they make
it lawful one year,
And forbidden another year,
Of months forbidden by Allah
And make such forbidden ones
Lawful. The evil of their course
Seems pleasing to them.
But Allah guideth not
Those who reject Faith. (IX: 37)

Without knowing, for example, when Ramadan falls, no man can obey the Qur’an’s call to fast during that month. Such a person might fast at the wrong time and fail to keep fast at the right time, failing to submit to Allah’s will. In this way, unbelievers add wrong practice to wrong belief, says the Qur’an.

Thus, the keeping of time by the lunar cycle is both critically important and distinctive to Islamic faith and culture, and provides an important reminder of the will of Allah.

In addition to the normal Islamiclunar calendar, various important adaptations of it have been used in various areas of the Islamic world. These were mainly used in the past but some are still significant today.

Because the Hegira calendar is purely lunar, it was inconvenient for fiscal and administrative purposes, especially during the pre-modern era, when most of the taxes collected were agricultural products. Remember, lunar calendar is not constant - for example, currently the fasting month of Ramadan falls roughly around late December or early January, but in a decade or so, it is going to take place during our summer. This of course presented some problems for the ruler: how are you supposed to levy agricultural taxes every year if your harvest times don't match your calendar? To undermine this problem, Muslim governments from early times worked out a series of solar adaptations of the Hegira year with Iranian, Christian and other months. The most important of these are:

1. The Turkish financial year (maliyye)

This was an adaptation of earlier fiscal calendars combining the Hegira date with solar year, and was introduced into the Ottomanrevenue administration in 1789 CE. The Maliye was a Julian year, with most of the old Syrian month names retained. However, this new calendar presented another problem: since the Islamic year is shorter than the Julian one, the counting of taxational years lagged behind the years of the religious calendar and had to be corrected from time to time. For this purpose, a practice of siwish ('changing') was adopted, whereby one solar year could be jumped over altogether.

At first, the Ottomans retained the old ByzantineNew Year on 1 September, but later on they moved the beginning of the year to 1 March. After this, each maliyye year had, in theory, the same number as the Hegira year during which it began, with the omission of one year every 33 years, i.e. whenever the 1st of March did not fall within the religious Hegira year (please refer to schmOOnkie pOOnks' write-up above). However, even this was not enough to avoid further problems, which mostly arose from the fact that the Ottomans collected taxes according to the Julian year but paid salaries according the the lunar year. This obviously led to difficulties with the bookkeeping whenever siwish became necessary.

Eventually the system broke down: the maliyye year 1287 (1871-2 AD) should have been followed by maliyye 1289 (1872-3), but for some reason the year 1288 was not left out, with the result that for the remainder of its history the maliyye calendar was out of step with the religious year. It was officially abolished with the adoption of the Western-style Christian era in 1927.

2. The Persian solar year

This was introduced in 1925 in Iran and is based on the Hegira, except it is calculated in solar years, using an adaptation of the old Iranian month names. To convert Gregorian solar years to Iranian, subtract 622 from dates 1 January-21 March; and 621 from dates 21 March-31 December. The New Year (nowruz), 1 Farvardin, falls in the third week of March. This calendar is currently used in Iran for all but purely religious purposes.

As stated above, the year begins at the spring equinox. The first six months have 31 days each, the next five have 30 and Esfand has 29 in an ordinary year and 30 in a leap year, giving 365 or 366 days in total. The inevitable difficulties arise when one tries to determine which years should be leap years. The rule, unlike that used with the Gregorian calendar, is quite complicated - there is no consistent method of calculation, or at least I have yet to see one.

For information about the old Persian calendar from which this system borrows both the names of its months and its function, see Zoroastrian Calendar.

3. The Turco-Mongol Calendar

Before coming to contact with Islam, the ancient Turks adopted a form of the Chinese luni-solar calendar, which then passed from the Uyghur Turks to the Mongols, who in turn introduced it in their medieval empire in Persia, where it was quite widely used alongside the Islamic calendar.

If you are familiar with the Chinese zodiac, you will already know that the Chinese lunar months begin not with the sighting of the new crescent, as in the Middle East, but a couple of days earlier with the calculated time of conjunction between the sun and the moon. The year begins while the sun is in Aquarius. The year is kept in pace with the solar year by the periodic intercalation of a thirteenth month, which is inserted whenever two new moons fall during the time that the sun is in one and the same zoological sign.

The Turkish names for the first (aram ay) and last (djakhshabat ay) months derive from Sanskrit or Iranian, the other ten months have no names but are merely counted, as in Chinese ("second moon" etc).

Years were counted according to the twelve-year cycle of Chinese astrology, where each year of the cycle takes the name of an animal. The Turkish and Mongol forms are as follows: